@article{DE_1988_24_12_a27,
     author = {N. P. Erugin},
     title = {The {Riemann} problem},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2187--2190},
     publisher = {mathdoc},
     volume = {24},
     number = {12},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1988_24_12_a27/}
}